It is recommended that you read through this section carefully before beginning any volume group conversion.

A mounted JFS or JFS2 file system cannot be converted. Unmount such file systems before proceeding with the conversion.

The vxconvert process converts LVM volume groups to VxVM disk groups in the default format. You can use the vxdiskadm menu to specify the default format. If you do not specify a default format, vxconvert uses the format that is compatible with the Cross-platform Data Sharing (CDS) feature (cdsdisk format).

This section outlines the process for converting LVM volume groups to VxVM disk groups. During the conversion process, all JFS or JFS2 file systems in a specified LVM volume group are converted to VxFS.

The conversion process involves many steps. Though there are tools to help you with the conversion, some of these steps cannot be automated. You should be sure to understand how the whole conversion process works, and what you will need to do in the process before beginning a volume group conversion.

The tool used for conversion is vxconvert. This interactive, menu-driven program walks you through many of the steps of the process of converting volume groups for use by VxVM. Using vxconvert can reduce the downtime associated with converting from LVM to VxVM. Without the vxconvert tool, the only possible method of in-place conversion would be to take full backups of user data, destroy the existing LVM configuration leaving only raw disks, recreate the configuration in VxVM, and then reload the user data.

The vxconvert process converts LVM volume groups to VxVM disk groups in place. This means, that the utility changes disks within LVM volume groups to VxVM disks by taking over the areas of the disks used for LVM configuration information, and creating the equivalent VxVM volume configuration information. User data, the portions of the disks used for databases, and so on, are not affected by the conversion. Both JFS and JFS2 data is converted during the conversion.

The act of conversion changes the names by which your system refers to the logical storage. Therefore, the conversion process is necessarily performed off-line. There can be no application access to user data in the volume groups undergoing conversion. Access to the LVM configuration itself (the metadata of LVM) must also be limited to the conversion process.